It depends on skin tone, more than shape?

I think dark usually works better, though if it's a flat black it can look fake / bad in some instances, but not too many.

Blond hair dye is criminally overused, and often fails.
Red hair dye has similar issues but not nearly to the same extent as blond,

If you're young and tasty, you can 'get away with' so many things aesthetic-wise. Though many more people think they have this status, or are aware of having lost this status, when it comes to hair color apparently.

Also there's maintenance, if you cannot maintain, perhaps don't go there.
Certainly don't go bold, that being the case.